Flotation of ores and materials therefor



Patented Dec. 4, 1923.

UNITED STATES 1.47am PATENT OFFICE.

ERVIN W. MCCULLOUGH, OF INDIANAPOLIS. INDIANA, AND ROGER E. WILSON, OF

MINNEAPOLIS, MINNESOTA, ASSIGNORS TO PETER C. REILLY, OF INDIANAPOLIS,-

IN DIAN A.

FLOTATION OF ORES AND MATERIALS THEREFOR.

No Drawing.

To all whom it may concern. Be it known that we, ERVIN W. MoCUL- LOUGH and Boone E. VVILsoN, citizens of the United States, residing, respectively, at Indianapolis, county of jIarion, State of Indiana, and at Minneapolis, county of Hennepin, State of Minnesota, have'invented certain new and useful Improvements in Flotationof Ores and MaterialsTherefor, of which the following is a specification.

The present invention relates to the flota tion of ores, and involves the employment of materials not heretofore used in ore flotation, which materials have been found to .be highly useful in producing by flotation, concentrates of an extraordinary richness, and also have the advantage of very completely removing the metal values from the tailings, so that the loss of metal values lI 1 tailings'is greatly reduced.

The flotation of ores, in which oily frothing agents are employed, is well known, and constitutes an important part of metallurgical o erations. The present invention aims at e ecting economies and improvements 1n the operation, by the employment of certain materials constituting the products of coal tar distillation, the particular novel materials bein two of the higher boiling distillates, which themeselves are known materials, being described in a atent of Peter C. Reilly, No. 1,230,782. hese materials may be briefly described as follows: The first is a distillate from coal tar coming over above the boiling point range of the green oil or anthracene oil. This distil late is orange in color, and comes over when subjected to a temperature in excess of 700 F. This material is of a waxy consistency at 70 F. and possesses an orange color at a specific gravity of about 1.14. The second material comes over after the orange colored material has passed from the still, say at about 1000 F. This material is a solid substance which is brittle at 70 F. The material can be shaved with a knife, producing a flaky powder or granular solid and when so cut presents a brilliant face having a brilliant garnet color. This material has a specific gravity of not less than about 1.22 at 70 F. These two materials are not recognized as constituents of ordinary coal tar and seemingly do not exist as such therein, but may be produced by the method set Application filed December 14, 1920. serial no. 430,775.

\Ve have found that these materials can be made to serve as ingredients of a flotation agent when dissolved in a suitable solvent. As to the solvent to be employed, various coal tar distillates up to and including the anthra/cene-oil fraction, can be used, in various proportions. It is often preferable to use therewith some frothing agent, such as pine oil. The frothing agent can, however, in some cases be entirely omitted.

For the purpose of illustrating our invention, it may be stated that the flotation of copper sulfide ores to separate the copper sulfide mineral from the gangue material may readily be accomplished in an ordinary flotation cell, bythe use of the above described coal tar distillates with a solvent, the necessary amount of frothing agent belng present. In this manner a froth is produced carrying the metal values, which froth overflows or is otherwise separated from the pulp in the flotation cell, and after so separating, the froth will readily break down, without necessity of using jets,

sprays or other extraneous means, for breakingdown the discharged froth, thereby producing a further economy in the flotation operation. We have found that from copper sulfide ores,.i1-, is possible to obtain a very clean high grade concentrate, thereby effecting an appreciable saving in reduced transportation, reduced smelting costs, and the like. We have also found that the agent as described is further capable of reducing the loss in the tailings to a minimum because of its greater selective powers.

For the purpose of illustration, the following examples of the use of specific ore flotation agents, in accordance with the present invention are given, it being understoodthat the invention is by no means restricted to such specific examples:

'Eaeample 1.-For producing an agent suitable for flotation of copper sulfid from relatively poor ores containing a gangue consisting largely of porphyry, say one pound of the orange waxy material and one pound of the garnet solid material, as above described, are mixed with 4.6 pounds of the balance of the coal tar distillates, the mixing preferably being done at above 100 F. About two pounds of this mixture was used, in a particular example, per ton of ore, using a laboratory flotation machine; r

A articular ore was treated with this mixture, containin about 40 pounds of total copper per ton. he tailing ran about 1.6 pounds of sulfid copper per ton.

In the procedure given in this example, the proportion between orange material and garnet material and the solvent can vary widely. The amount of mixture used per ton of ore likewise can vary widely. Amounts between about 0.5 pound and about 6 pounds per ton-of ore have been used with good results.

Example 2.-For producing an agent suitable for commercial flotation of copper sulfid from very poor ores or tailings containing 14.4 pounds of copper per ton (partly as sulfid and partly as oxid, etc.) and having a gangue consisting largely of silicate rock, one pound of the garnet solid material, as above described, was mixed with 19 pounds of low gravity coal tar distillate (gravity les than 1.03), the mixing preferably being done above 100 F. No pine oil or other extraneous frothing' agent was used. About one to three pounds of this solution was used per ton of ore. In this test an acid circuit was employed contain ing sulfuric acid.

In an actual commercial test under these velg unfavorable conditions, we were able to oat about two-thirds of the total copper present, using about 2.5 pounds of the oil mixture per ton of ore. The copper remaining in the tailing wa largely in the oxide form.

In other similar tests,.without pine oil, the acid was omitted.

Example 3.For producing an agent suitable for flotation of copper sulfid from a medium rich flotation ore containing 36.2 pounds of copper per ton and having a siliceous gangue, about one pound of the garnet solid material as above described, was mixed with 18 pounds of the light coal tar distillate (gravity less than 1.03), the mixing preferably bein done above 150 F. About one pound of t is was used per ton of ore with a small amount of pine oil as a frothing agent.

In this operation we obtained, in a commercial run, a concentrate containing about 52% copper, while the tailings were found to contain only about 0.11% copper, existing as sulfid. In this test we recovered 94.5% of the total copper sulfid in the ore under treatment.

Example ,.-One part of the orange colored material was dissolved in nine parts of lower gravit coal tar distillates (gravity below 1.14) and a small amount of pine oil added. An ore containing 17 .4 pounds of total copper per ton wa treated with the above mixture, using about one pound of the mixture per ton of ore. This left a tailing containing about 2.8 pounds of cop per per. ton (mostly as oxid, etc.) and gave ravaeeo a concentrate containing 87% of the total copper contained. in the original ore.

In the above, examples we have referred to a number of solvents for the hereindescribed coal tar distillates coming over above 700 F. Of the various possible solvents, we prefer to employ coal tar distillates coming over below 700 F. These may include the lighter distillates only, or the heavier distillates only, or the intermediate distillates only, or various mixtures of any or all of these 'distillates. These distillates or mixtures may be used either crude or refined or after the addition thereto or the removal therefrom of certain materials, or after other treatment. to enumerate all of the specific mixture of coal tar distillates which can be used, but generally speaking any coal tar distillate coming over below 700 F., or any mixture of two or more of-suchdistillates will answer the purpose.

While we'have particularly stated that these distillates will serve, we do not limit ourselves thereto but can use any solvent, as, for instance, water gas tar distillates, oil tar distillates, or other solvents.

What is claimed is:

1. The herein described composition of matter suitable for flotation purposes containing a coal tar distillate which distills at above 700 F., and a solvent which will permit flotation.

2. The herein described composition of matter suitable for flotation purposes containing a coal tar distillate which distills at above 700 F., a solvent which will permit' flotation, and a suitable frothing agent.

3. The herein described composition of matter suitable for flotation purposes containing a coal tar distillate which distils above 700 F., a solvent which will per; mit flotation, and pine oil.

4. The herein described composition of matter suitable for use in flotation, containtaining those coal'tar products which distill at temperatures above 700 F., and a solvent therefor, said solvent being an organic liquid which will permit flotation.

5. The herein described composition of matter suitable for use in flotation, contain taining those coal tar products which distill at temperatures above 700 F., a solvent therefor, said solvent being an organic use in flotation, containing as its essential constituent, the heroin descri coal tar or containing those distillates, derived from coal tar oil up to and including the anthracene or green oil fraction.

9. The herein described composition of matter suitable for flotation containing those coal tar products which distill at temperatures above 700 F., and a solvent therefor comprising a distillate from coal tar distilling below 700 F.

10. The herein described composition of matter suitable for flotation containing those coal tar products which distill at temperatures above 700 F and a solvent therefor containing any portion of the distillates derived from coal tar up to and includingv product, which is a garnet colored material the anthracene or green oil fraction.

11. The herein described composition for use in flotation, containing as its essential constituent the herein described coal tar product which is a garnet colored material, solid and brittle at 70 F., and which has a specific grayity not substantially less than 1.22, such product being dissolved in a solvent, such solvent being one which will not inhibit flotation.

12. The herein described composition of matter suitable for flotation, containing distillates of coal tar which distill between about 700 F. and about 1000 F. dissolved in a solvent, such solvent being one which will not inhibit flotation.

13. An improvement in the flotation of ore material which comprises floating in a liquid containing a brittle solid coal tar distillate coming over substantially about 700 F. and a solvent for such distillate, such solvent including a frothing agent.

18. An improvement in the flotation of ore materials, which comprises floating in a liquid containin a coal tar distillate distilling above 7 F. in solution in a coal tar distillate distilling below 700 F.

19. An improvement in the flotation of ore materials, which comprises floating in' a liqluid containing a coal tar distillate distil in above 700 F. in solution in a coal tar istillate distilling below 700 F. together with a; frothing agent.

20. The herein described com osition for use in flotation, containing as 1ts essential constituent, the herein described coal tar] solid and brittle at 70 F. and which has a specific gravity not substantially less than 1.22, a solvent therefor, and a frothing agent.

21. The herein described composition of a matter suitable for flotation containing those coal tar products which distill at temperatures above 7 00 F., a solvent therefor containing those distillates, derived from coal tar oil up to and including the anthracene or green oil fraction, and a frothing agent.

22. The hereindescribed composition for use in flotation, containing as its essential constituents, the herein described coal tar product, which is a garnet colored material solid and brittle at 70 F., and'which has a specific gravity not substantial] less than 1.22, and also containing the erein described coal tar product which is a waxy mass at 70 F., and has a specific gravity of from 1.14 to 1.22, together with a solvent I for such two products, such solvent being one capable of permitting flotation.

In testimony whereof we have signed our names to this specification.

ERVIN W. McCULLOUGH. ROGER E. WILSON. 

